Vo!* XXXX 
DECEMBER 15, 1924 
No. 12 
CONTENTS 
Pag® 
Life-History Studies of the Tobacco Flea-Beetle in the Southern Cigar-Wrapper 
District - • - - - - - - - - « - 575 
F. S. CHAMBERLIN, J. N. TENHET, and ADAM G. BOVTNG 
The Differentiation of Primary Isolations of Bacterium melitensis from Primary 
Isolations of Bacterium abortus (Bovine) by Their Cultural and Atmospheric 
Requirements - - - • — - • * - - • - - 585 
JOHN M. BUCK 
Feed Cost of Milk Production as Affected by the Percentage Fat Content of the 
Milk • - - - - - - - - - - - - - - 593 
W. L. GAINES 
Relation Between the Diet, the Composition of the Blood, and the Secretion of 
Milk of Dairy Cows • - - - - - - - - - - 603 
C. A. CARY and EDWARD B. MEIGS 
PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE 
WITH THE COOPERATION OF THE ASSOCIATION 
OF LAND GRANT COLLEGES 
WASHINGTON, D. C. 
GOVERNMENT PRINTING OFFICE 
1925 
